I cannot speak for NeurIPS in particular. But most academic conferences are just there to know what is out there, not to gain a deep understanding of the topic. Every session (keynotes aside) is very rushed. Each speaker maybe gets 10 minutes to present his paper. That is usually enough to get a general idea what this paper is about but not nearly enough to really understand it. I usually just sit in these sessions and make a note that I this might be an interesting paper to read later.

And don‘t expect workshops to be a step by step introduction into the subject. You still need to have good general understanding of the subject to benefit from one. I‘ve also been at conferences where „workshop“ wasn‘t intended to be a workshop for participants but for the authors (which usually were new researchers). Those were papers with interesting approaches but not so good results. And the audience was encouraged to contribute ideas that the author could try.

Just to be sure: I‘m not saying that it wouldn‘t be worth attending such a conference. I‘m just saying that you should have the right expectations.